This diff refactors the uio to mbuf code to make use of bigger buffers (up
to 64k) and also switches the MCLGET to use M_WAIT like the MGET calls in
the same function. I see no point in not waiting for a cluster and instead
chain lots of mbufs together as a consequence.
This makes in my opinion the code easier to read and allows for further
optimizations (like using non-DMA reachable mbufs for AF_UNIX sockets).
This increased the preformance of loopback connections significantly when
I tested this at n2k16.
--
:wq Claudio
Index: kern//uipc_socket.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_socket.c,v
retrieving revision 1.152
diff -u -p -r1.152 uipc_socket.c
--- kern//uipc_socket.c 13 Jun 2016 21:24:43 -0000 1.152
+++ kern//uipc_socket.c 12 Aug 2016 14:07:36 -0000
@@ -373,6 +373,8 @@ bad:
return (error);
}
+int m_getuio(struct mbuf **, int, long, struct uio *);
+
#define SBLOCKWAIT(f) (((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
/*
* Send on a socket.
@@ -395,10 +397,7 @@ int
sosend(struct socket *so, struct mbuf *addr, struct uio *uio, struct mbuf *top,
struct mbuf *control, int flags)
{
- struct mbuf **mp;
- struct mbuf *m;
long space, clen = 0;
- u_long len, mlen;
size_t resid;
int error, s;
int atomic = sosendallatonce(so) || top;
@@ -475,7 +474,6 @@ restart:
goto restart;
}
splx(s);
- mp = ⊤
space -= clen;
do {
if (uio == NULL) {
@@ -485,52 +483,14 @@ restart:
resid = 0;
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
- } else do {
- if (top == 0) {
- MGETHDR(m, M_WAIT, MT_DATA);
- mlen = MHLEN;
- m->m_pkthdr.len = 0;
- m->m_pkthdr.ph_ifidx = 0;
- } else {
- MGET(m, M_WAIT, MT_DATA);
- mlen = MLEN;
- }
- if (resid >= MINCLSIZE && space >= MCLBYTES) {
- MCLGET(m, M_NOWAIT);
- if ((m->m_flags & M_EXT) == 0)
- goto nopages;
- if (atomic && top == 0) {
- len = ulmin(MCLBYTES - max_hdr,
- resid);
- m->m_data += max_hdr;
- } else
- len = ulmin(MCLBYTES, resid);
- space -= len;
- } else {
-nopages:
- len = ulmin(ulmin(mlen, resid), space);
- space -= len;
- /*
- * For datagram protocols, leave room
- * for protocol headers in first mbuf.
- */
- if (atomic && top == 0 && len < mlen)
- MH_ALIGN(m, len);
- }
- error = uiomove(mtod(m, caddr_t), len, uio);
+ } else {
+ error = m_getuio(&top, atomic,
+ space, uio);
+ space -= top->m_pkthdr.len;
resid = uio->uio_resid;
- m->m_len = len;
- *mp = m;
- top->m_pkthdr.len += len;
- if (error)
- goto release;
- mp = &m->m_next;
- if (resid == 0) {
- if (flags & MSG_EOR)
- top->m_flags |= M_EOR;
- break;
- }
- } while (space > 0 && atomic);
+ if (flags & MSG_EOR)
+ top->m_flags |= M_EOR;
+ }
s = splsoftnet(); /* XXX */
if (resid == 0)
so->so_state &= ~SS_ISSENDING;
@@ -539,9 +499,8 @@ nopages:
top, addr, control, curproc);
splx(s);
clen = 0;
- control = 0;
- top = 0;
- mp = ⊤
+ control = NULL;
+ top = NULL;
if (error)
goto release;
} while (resid && space > 0);
@@ -556,6 +515,76 @@ out:
if (control)
m_freem(control);
return (error);
+}
+
+int
+m_getuio(struct mbuf **mp, int atomic, long space, struct uio *uio)
+{
+ struct mbuf *m, *top = NULL;
+ struct mbuf **nextp = ⊤
+ u_long len, mlen;
+ size_t resid = uio->uio_resid;
+ int error;
+
+ do {
+ if (top == NULL) {
+ MGETHDR(m, M_WAIT, MT_DATA);
+ mlen = MHLEN;
+ m->m_pkthdr.len = 0;
+ m->m_pkthdr.ph_ifidx = 0;
+ } else {
+ MGET(m, M_WAIT, MT_DATA);
+ mlen = MLEN;
+ }
+ /* chain mbuf together */
+ *nextp = m;
+ nextp = &m->m_next;
+
+ resid = ulmin(resid, space);
+ if (resid >= MINCLSIZE) {
+ mlen = ulmin(resid, MAXMCLBYTES);
+ MCLGETI(m, M_WAIT, NULL, mlen);
+
+ if ((m->m_flags & M_EXT) == 0) {
+ /* should not happen */
+ m_freem(top);
+ return (ENOBUFS);
+ }
+ mlen = m->m_ext.ext_size;
+ len = ulmin(mlen, resid);
+ /*
+ * For datagram protocols, leave room
+ * for protocol headers in first mbuf.
+ */
+ if (atomic && top == NULL && len < mlen - max_hdr)
+ m->m_data += max_hdr;
+ } else {
+ len = ulmin(mlen, resid);
+ /*
+ * For datagram protocols, leave room
+ * for protocol headers in first mbuf.
+ */
+ if (atomic && top == NULL && len < mlen - max_hdr)
+ MH_ALIGN(m, len);
+ }
+
+ error = uiomove(mtod(m, caddr_t), len, uio);
+ if (error) {
+ m_freem(top);
+ return (error);
+ }
+
+ /* adjust counters */
+ resid = uio->uio_resid;
+ space -= len;
+ m->m_len = len;
+ top->m_pkthdr.len += len;
+
+ /* Is there more space and more data? */
+ } while (space > 0 && resid > 0);
+
+ *mp = top;
+ return 0;
}
/*
